fluidcushions the suspended organs thereby preventing injury, In soft-bodied coelomates, the fluid acts as a hydrostaticskeleton, The internal organs can grow andmove independently of the outer body wall

protostome

–The blastopore becomes the mouth

–Ex. Mollusks, annelids, arthropods

spiral and determinate cleavage

Deuterostomes

–The blastopore becomes the anus

–Ex. Echinoderms, chordates, HUMANS

-radial and indeterminate cleavage

Indeterminate cleavage

–Each cell produced in early division can form acomplete embryo

–Identical twins develop when the mass of cell dividedinto two

–Source of stem cells

–Deuterostomes

Determinate cleavage

–Development fate of each cell is determined VERY early,as early as 4 cells

–Protostomes

Radial cleavage

–Cleavage planes are paralles or perpendicular to verticle axis

–Cells are aligned one directly above the other

–Deuterostomes

Spiral cleavage

–Planes of cell division are diagonal to the verticalaxis of the embryo

–Small cells lie in grooves

–Protostomes

CirculatorySystem

Internal distribution of materials

diffusion

–Simple animals do not need specialized structures fornutrient/gases transport because the nutrients/gases have only a short distanceto diffuse.

-functions in both digestionand distribution of nutrients throughout the body (the vascularpart of word)

Digestion in a Hydra

Digestion begins in the gastrovascular cavity and iscompleted intracellularly after small foodparticles are engulfed by the gastrodermal cells.

complete digestive tract

-tube within a tube; mouth to anus

-Digestionoccurs in one area of the digestive tract while absorption occurs in anotherarea.

earthworm digestion

pharynx that sucks food in through the mouth.Food passes through the esophagus and is stored and moistened in the crop.The muscular gizzard, which contains small bits of sand and gravel, pulverizesthe food.Digestion and absorptionoccur in the intestine, which has a dorsal fold, the typhlosole,that increases the surface area for nutrient absorption.

grasshopper digestion

a foregut, with an esophagus and crop; a midgut; and hindgut.Food is moistened and stored in the crop, but most digestion occurs in the midgut.Gastricceca, pouches extending from the midgut, absorb nutrients.

bird digestion

three separate chambers – the crop, stomach, and gizzard , where food is pulverized and churnedbefore passing into the intestine.The bird’s crop and gizzard function very much like those of anearthworm.In most birds, chemicaldigestion and absorption of nutrients occur in the intestine.

small intestine (human)

many folds to increase surface area of absorption, covered in villi which is very thin and filled with capillaries for easy nutrient absorption

Excretion

–waste disposal of metabolic wastes

•Breakdown of proteins and nucleic acids produce ametabolic waste product, ammonia, that is very toxic even in small amounts

osmoregulation

–Regulate solute concentrations and balance the gain andloss of water

saltwater animals problems and fixes

not enough water, getting rid of salt. let out a lot of salt in urine but minimal water and drinking salt water and letting salt out of gills

freshwater animal problems and fixes.

too much water get rid of; large amounts through urine taking in not as much water through mouth

excretion steps

1. filtration- everything sent to tube to be sorted through

2. reabsorption- absorb what you want

3. secretion- toxins sent out too

4. excretion- leaves body

–Protonephridia and Excretory Canals

•Used mainly for osmoregulation

•The beating of the cilia at the ends of the tubulesdraws water and solutes into the tubules.As the water and solutes pass through the tubules, most of the solutesare reabsorbed.The water isexcreted through pores.

•Platyhelminthes, rotifers, nematodes, nemerteans

ex: of Protonephridia:

the flame-bulb system of a planarian

Metanephridia and MalpighianTubules

–Remove nitrogenous wastes and have a function in osmoregulation

–The beating of cilia in the ends of the tubulescollects fluid from the coelom.As thisfluid moves along the tubule, solutes are reabsorbed.Wastes are dumped outside the body.

–In insects, most of the water is reabsorbed along withthe solutes, so very dry nitrogenous wastes are excreted.

–Mollusks, annelids, arthropods

Nephrons

•in kidneys

–Remove nitrogenous wastes and have a function in osmoregulation

–Nutrients, salts, and water are reabsorbed whilenitrogenous wastes and other substances (H+ ions, drugs, creatine) are excreted.

Vertebrates

wastes can exit through

nephridiopore

flame cells

found in flat worms part of protonephridia, the beating of the cilia at the ends of the tubules draw water